ABSTRACT Emergency Departments (ED) care for 15 million adolescents each year, the majority being poor, minority, and participating in risky sexual behaviors.1?6 Despite a growing interest in expanding the role of the ED to provide preventive care, ED providers identify limited resources and time constraints as barriers to the implementation of public health interventions.7,8 Novel interventions are needed that fit efficiently within the ED workflow.9 Our prior work recently highlighted a significant public health problem?a particularly high risk of unintended pregnancy among our adolescent ED population.3 We demonstrated that 1 in 5 adolescent females who use our ED are expected to become pregnant in the following year, a risk five times the national average and primarily due to contraceptive non-use. These adolescents infrequently follow up for reproductive care when referred, yet are receptive to ED-based pregnancy prevention interventions, particularly using text messaging.10?13 To date, no intervention has successfully increased contraception use among this high risk, hard-to-reach ED population. Lauren S. Chernick, MD, MSc, is an Assistant Professor of Pediatrics in the Division of Pediatric Emergency Medicine at Columbia University Medical Center and is committed to improving the reproductive health outcomes of underserved adolescents using the ED for medical care. During the proposed 3-year Mentored Patient- Oriented Career Development Award (K23), Dr. Chernick?s knowledge and skills will be augmented through the guidance of an interdisciplinary team of mentors and advisors committed to her academic independence. Dr. Chernick?s multi-disciplinary career development plan will focus on the following four key modules: 1) the use of mobile technology for intervention delivery and evaluation; (2) advanced clinical trial design and methodology; (3) the ethics and regulations of researching adolescents; and (4) research dissemination skills and professional development. Dr. Chernick?s training activities will be complemented by an original project that will accelerate the application of these skills. In Aim #1, she will conduct a pilot randomized control trial of a user-informed, theory-based, personalized, interactive, pregnancy prevention text messaging intervention (entitled Dr. Erica) to determine its feasibility, acceptability and potential efficacy. We hypothesize that high risk adolescent female ED patients who receive Dr. Erica will more often initiate contraceptives than those females who receive standard outpatient referral alone. In Aim #2, she will conduct a qualitative analysis to identify barriers and enablers to the implementation of reproductive health interventions across four diverse EDs in the US. This data will inform a multi-center clinical trial with sufficient power to measure clinically significant changes in contraceptive initiation. Dr. Chernick?s K23 research and training will culminate in the preparation of a R01 application to fund this definitive trial. Ultimately, a text messaging intervention that is effective and automated can be utilized by other EDs as a reproducible and scalable means to promote reproductive preventive care, decrease unintended teen pregnancy, and improve adolescent health outcomes throughout the US.